It once seemed as if Washington’s most powerful anti-tax crusader had the Republican Party firmly in hand. Signing Norquist’s public pledge not to raise taxes was almost mandatory in GOP politics. Nine of the 10 candidates initially vying for the Republican presidential nomination, including Mitt Romney, signed on, as did candidates for local, state and national office.

Some of them even signed Norquist’s vow in public ceremonies, then gave him the originals to store in the vault of his group, Americans for Tax Freedom. The best signatures went on the office wall like trophies.

Norquist’s power came from a threat that he didn’t hesitate to brandish: Any member of Congress who broke the pledge would be called to account before voters, preferably in a GOP primary against someone more reliable.

But an increasing number of Republicans are sidling away from Norquist’s pledge and reassessing their resistance to any kind of tax increase. Before this month’s election, Norquist counted 238 members of the House of Representatives as signers of his pledge, a majority of the total of 435. But no more than 212 members of next year’s House consider themselves bound by the pledge — fewer than a majority.

Some of Norquist’s signers lost their seats. Some newly elected Republicans say they see no reason to sign a formal pledge on taxes. And at least six House members who once signed say they no longer consider themselves bound by it.

Even more striking, an increasing number of prominent Republicans are dismissing Norquist as a pest. House Speaker John A. Boehner (R-Ohio) has referred to him as “some random person.” Sen. John McCain, R-Ariz., says Norquist’s power has been “broken.” And in the unkindest cut for any Washington idea-monger, Sen. Tom Coburn, R-Okla., dismissed Norquist as inconsequential. “It doesn’t matter what he says,” Coburn told MSNBC in July.

Not surprisingly, Norquist is fighting back. He says he’s confident that the Republican leadership in Congress is still committed to rejecting any net increase in taxes. And when I asked him this week about his critics in the Senate, he was dismissive. None of them “are considered thought leaders on economic issues,” he said. That’s not a good sign. Describing senators from your own party as dim bulbs isn’t normally how lobbyists win friends and influence people.

Moreover, when he was asked about the signs that Republicans are wavering — like Boehner’s signals that he is ready to accept increased revenue as part of a fiscal compromise — Norquist simply denied any threat.

“The Rs are holding,” he insisted. “The fantasy is that the Republicans would cave on marginal tax rates,” he said. “They’re nonnegotiable.”

It’s true that Republicans have held firm so far against President Obama’s demand to raise marginal tax rates on the top 2 percent of taxpayers. But those same Republicans are talking freely about other measures to increase revenue, including proposals to limit tax deductions and exclusions.

Page 2 of 2 - And those are violations of Norquist’s pledge too. The pledge explicitly rules out “any net reduction or elimination of deductions and credits, unless matched dollar for dollar by further reducing tax rates.” In other words, any change in the tax law that increases federal revenue is out.

Lately, however, more Republicans are concluding that increasing revenue is the price of a deal with Obama to avoid the brutal combination of tax increases and spending cuts scheduled to take effect next year if Congress doesn’t act. Even Senate GOP leader Mitch McConnell, R-Ky., usually a hard-liner, said last week that he was “open to new revenue” as long as it was accompanied by cuts in Medicare and other entitlement programs.

As for the exit polls that appeared to show a majority of voters on Nov. 6 supported Obama’s position on taxes, Norquist has a one-word answer: “Wrong.” Plenty of other polls, he says, show that people still don’t like the idea of taxes going up.

Norquist insists that if Republicans will only hold firm in the coming negotiations, the president will fold, as he did in 2010. Obama “will eventually have to extend the tax cuts as is,” he said.

Norquist’s power has derived mostly from the threat that he would expose tax-raisers to their constituents, who would then express their anger at the polls. But that threat seems emptier now because of a handful of Republicans like Scott Rigell. Last spring, Rigell, a freshman House member from Virginia Beach, Va., decided the pledge didn’t make sense any more. He publicly renounced it. He held a series of town halls and interviews in his district explaining his decision.

And on election day, he won easily.

Doyle McManus is a columnist for The Los Angeles Times. Readers may send him email at doyle.mcmanus@latimes.com.